Electrical instrument for electrically transmitting indications.



. M. DURR. A ELECTRICAL INSTRUMENT FOR ELECTRICALLY TRANSMITTING INDICATIONS. APPLICATION FILED AUG.26. 1913.

1,146,486. I I Patented July 13, 1915.

-' NITED, sTATEs PATENT OFFICE. J

MAX mine, or FRI' DE AU, NEAR. BERLIN, GERMANY, Assmnon To SIEMENS & HALSKE as, or BERLILL'GERMANY, A CORPORATION or GERMANY.

ELECTRICAL INSTRUMENT FOR ELECTRICALLY TRANSMITTING INDICATIONS.

vented certain new and useful Improvements in Electricalv Instruments for. Electrically Transmitting Indications, of which the following is a-full, clear, and concise de-' scription.

My invention relates-to an electrical measuring instrument which is especially used in connection with instruments having. their pointers mechanically operated, such as Qmanometers, the indication of which shall be electrically transmitted upon an electrical measuring instrument, preferably one of the registering type. Ordinarily in this case the pointer whose position is to be transmitted is moving over'a series of contacts into which resistances are inserted so that according to the number of contacts switched indications obtained at the electrical measjacent turns upon which the pointer is movi of the resistance, this arrangement permit-,

ing by means of a contact member having a dullor broadedge. Thus, the pointer or contact member ,will be contacting in every moment with a plurality of adjacent turns ting a transmissionof even very small mo: tions of the pointer upon the indicating device. In the scale of the instrument Whose motions areto be registered, for instance of a manometer, by the apparatus according to my invention there may yet be entirely proportionate deflections of the registrating instrument attained, in such a manner that the cross-section of the insulating body carrying the resistance turns is made non-uniform,

Specification of Letters Iia'tent.

and this in dependence from the non-uniformity of the scale of said first instrument so that the amount of resistance inserted between adjacent contacts varies according to the circumference of the variable cross sectlon of the insulating body;

- ln order, now, to do away with the mechanlcal reslstance of the contact which is an impediment for the free motion of the pointer, I provide means for making the contact periodically and only for a short tlme, so that the registration at the integrating instrument will present itself as an interrupted line. This may be done in such a way that thecontact arm is depressed either mechanically by a clip or lever whichis actuated in regular intervals, or also electri- Patented July 13, 1915.

Application filed August 26, 1913. Serial No. 786,701.

cally by periodically exciting an electroproper intervals by electro-magnetic attractlon. Assuch pointer instruments are often employed in moist rooms the resistance wire as well as the contact cooperating therewith are preferably made from nonoxidizing metals or their alloys. V

In the drawing forming part of this specification I have shown an embodiment of my invention of which' Figure 1 is a longitudinal section of an instrument according to my invention. Fig. 2a plan view of the same instrument, and Fig. 3 a front view of the resistancebodv of the construction shown in Figs. 1 and 2.

Referring now more particularly to the drawing, thepointer e, for instance of a manometer, is mounted upon an 'axle' a which is. coupled by a spring f with the central part b of the pointer 0; This pointer c is made of resilient material, and is provided at its end with an edge-like contact preferably made from. an alloy of gold and silver or from platinum. For being de-' pressed upon the resistance, iron pieces 0 and e are attached to the under side of the pointer, which are attached at intervals by an electro-magnet as described below. The contact edge 8 during motion of the pointer .2 moves overa resistance body w consisting of a wire wound upon an insulating body having the form of a ring open at one place. The insulation of this resistance wire, which is also. preferably made from non-oxidizingare bridged by the iron bodies e and e which are fastened upon the contact arm 0. soon as current is sent through the winding i of this magnet, which may be done periodi- V cally, such as .by a clock work, this magnet j I cally transmitting indications by c'han es of resistance,.the combination oi -,aring-s aped will attract the armature e, therewith pressing" the contact edge 8 vupon the resistance body '11:, thus making temporarily a circuit from'the battery B over-the registering instrument M,'- which is then connected .in circuit with the contact arm 0. An arrangement of'the latter kind I have incorporated in Fig. 1 bya wheel 10 which is provided with a nuinberof projections or teeth 11 and which is rotated, as indicated by the arrow, by a clock work or similar device so that at even intervals a circuit will be established for exciting the Windingi of the electro-magnet m by the'battery 13 over the contact spring. 12 and the slip-ring 13 and brush or contact-spring 14, as shown in Fig. 1 of the drawing. Also, according to the position of the pointersrs and c, a current will flowthrough the instrument M, said current depending-upon the amount of re-- sistance, which is at the time included in the circuit of the battery"B.-- This, obviously will'cause an indication or registration at the instrument M corresponding to the an- 7 gle of deflection of the polnter z.

., When employing a registering instrument- M, integrating periodically such as'by means of a .fall lever, the operation of the current. closing deviceof the magnet m'is so timed that the excitation of this magnet will take place in the same moment in which, the

pointer of the registering instrument is kept depressed by the fall lever. J

' In orderto compensate the non-uniformity of the scale, the insulating bodycarrying the resistance is made with a larger crosssection at its ends, as indicated at it, so that at these places there will correspond to the same angle of deflection of the arm a a greater change of resistance than at other places of the resistance body. This change in dross-section of the insulating body which .is shown as an increase of cross-section at.- the ends of the ring may of course be difier ent from that shown in the drawing and may be closely adapted to the particular degree' 'of non-uniformity throughout the scale of any instrument. In this manner I attain that the indications at'the measuring instruine'nt M will be made to follow a uniform scale, whatever be the degree of nonumformity of the scale of the firstinstrument, that is to say of the deflection of the pointer z. Having Patent of the United States 0 thus described my invention, I claim as new and desire to secure by Letters 1. In an electrical instrument for electrip insulating body wound withresistanceawi're inclosely adjacent turns, the cross-section of said insulating body being such asto compensate non-uniformity in the deflections of saidinstrument, and a devicecontactingwith said resistance-Wire and carried by the pointer of said instrument.

2. In an electrical instrument for electrically transmitting indications by. chan es of g V resistance, the combination of a ring-s aped ment,'and means for depressing said contact arm at intervals upon said resistance wire for making circuit with an .electrical meas--- uring device.-

3. In an electrical instrument for electri cally transmitting indications by changes ofresistance, the combination of a ring-shaped 9o arm normally at some-distance from said reinsulating body which is wound with resistance wire in-closel'y adjacent turns, a contact sistance wire and carried by the pointer of l said instrument, and electro-magnetic'means for bringing said contact arm in contact with said resistance wire for making circuit with an-electrical measuring device.

cally'transmitting indications by changes of y 4. In an electrical instrumentfor electrip 4 resistance, the combination ofaring-shaped insulating body which is wound with resist ance wirein closely ad1acentturns, a con-. tact arm for contacting w th said resistance wire resiliently carried by. the pointer-of said instrument, and electro-magnetic means for periodically bringing saldcontact arm,

inzcontact with said resistance wire.

' In testimony. whereof I have hereunto set my signature in presence of two subscribing no witnesses.

. Witnesses:

HENRY HASPER, ARTHUR Sormonnnn.

DURR." i a 

